Liquidproof seam for protective apparel

ABSTRACT

Liquidproof seams are formed between laminates, most preferably those having a complex textile structure on the sealing side of the laminate, where at least a portion of the complex textile in the sealing region is removed, such as by skiving, to reduce the thickness in the seam, or sealing region, prior to the creation of a durably sealed liquidproof seam.

RELATED APPLICATIONS

The present application is a divisional application of U.S. patentapplication Ser. No. 10/686,248, filed Oct. 15, 2003, allowed.

FIELD OF THE INVENTION

This invention relates to the production of liquidproof protectiveapparel created from laminates, most preferably those having a complextextile structure on the sealing side of the laminate, where liquidproofseams are created by removal of a portion of the textile, such as byskiving, in the seam, or sealing, region prior to the creation of adurably sealed liquidproof seam.

BACKGROUND OF THE INVENTION

The use of coated textile composites or laminates of textiles and liquidprotective barrier membrane layers to create liquidproof protectiveapparel is well known in the industry. The most common of theseapplications is waterproof breathable apparel. Typical examples arelaminate materials sold by W. L. Gore and Associates, Inc. under theregistered trade name GORE-TEX, which contain a waterproof breathablefilm laminated, or bonded, to one or more textile layers. Theselaminates are fabricated into apparel and sold as GORE-TEX® garments andthe like. Coated textiles can also be used in textile composites forthese same purposes. Both coated textiles and protective barriermembrane, or film, laminates will be collectively referred to hereafteras “laminates” solely for convenience of description.

Pieces or panels of these laminates are joined together to form garmentsand other similar textile structures. For the garments to be liquidproofand protective, there is a need to seal the seams where the panels oflaminate are joined together. The joining of these laminate panels istypically done by first sewing the laminates together using conventionalsewing techniques. Liquidproof sealing of these sewn seams is thenaccomplished by the application of a seam seal tape having athermoplastic hot melt adhesive which seals to the surface of thecoating or protective barrier film and creates a seal over the sewingholes and the area where the layers join between the stitches. The seamseal tape may be heated, for example, using a nozzle to direct a streamof hot air so as to melt the adhesive. The tape is then applied over theseam and both are passed through the nip of a pair of pressure rollersin order to squeeze the molten adhesive onto the protective layersurface to ensure good bonding of the tape to the surface. For aestheticreasons, the seam sealing tape is generally applied to the interior of agarment so that it is hidden from view. Less common sealing techniquessuch as gluing and welding are also known in the art.

In many applications, it is desirable to use a textile layer on bothsides of the protective membrane or coating, either to extend thedurability of the protective layer, or to improve the aesthetics andsensorial comfort of the finished apparel. These laminates are referredto as three-layer constructions, or three-layer laminates. For example,very often for reasons of comfort and appearance the liquidproof,breathable laminate is provided with a knitted liner layer (i.e., thelayer which faces the wearer), which is somewhat soft to touch and thus,provides improved comfort in contact with the wearer.

Unfortunately, the liner layers which can be used with conventionalliquidproof garments are very limited, as problems with creating adurable, liquidproof seal arise when layers with a complex textilestructure are used. As used herein, the term “complex textile structure”is intended to refer to textiles with a fiber, or filament, structure(whether mono-filament or multi-filament) having a tortuous path throughwhich adhesives or sealants have limited ability to penetrate to theprotective barrier layer and to encapsulate the filaments of the textilelayer in order to form a liquidproof seam. For the purposes of thisinvention, fibers and filaments are considered to be usedinterchangeably and can include, for example, staple fibers. Complextextile structures can include, for example, wovens, nonwovens, knits,and brushed, fleeced or otherwise napped (i.e, any suitable raisedsurface) forms thereof. These complex textile structure materials oftentend to be bulkier or thicker than conventional liner layers and aremore desirable since they tend to be more comfortable to the wearer.

As noted above, the use of textile constructions with three layers, andpossibly even more layers in some instances, creates added difficulty informing a liquidproof seam. Not only does a seal need to reach theprotective barrier layer surface, but also the structure of the textileitself needs to be sealed or encapsulated to prevent liquid from wickingor seeping along the textile fibers and exiting beyond the boundary ofthe liquidproof seam. Thus, the seam sealing of such three-layerfabrics, such as those having a complex textile structure for the innerlining layer, has posed significant problems in the prior art.

A first problem is that while the application of heat and pressure tothe seam sealed tape is generally effective to force the molten adhesivethrough the liner layer into good contact with the underlying membranelayer (thereby filling the spaces between adjacent yarns in the linermaterial), the seam seal adhesive does not penetrate within theinterstices of the yarns themselves. As is known, yarns are made up ofmultiple filaments etc., which have interstices between adjacentfilaments. These interstices provide a path along which liquid can wickor weep from the seam to the inside of the garment. This is depicted inmore detail with reference to FIGS. 1 and 2, described below. Thus,liquid water entering into the seam through a gap between the adjacentpieces of material or through holes in the rows of stitching, is able towick laterally out of the seam through the interstices in the yarns ofthe liner material itself. Therefore, the seam is not completelyliquidproof, particularly under severe weather or challenge conditions.

FIGS. 1 and 2 illustrate the problems with conventional seam sealingprocedures. FIG. 1 shows a series of steps for forming a conventionalseam with the application of seam sealing tape. It is to be understoodthat the formation of the seam can generally be carried out usingconventional sewing machines.

In step 1), two adjacent pieces of material 1 a, 1 b are overlappedalong a seam 2. In a second step 2), the seam is stitched with a row ofstitching 3. In a third step 3), the seam is folded over and a furtherline of stitching 4 is applied so as to form a flattened seam. This seamis not liquidproof, since liquid can ingress through the space betweenthe overlapped pieces of material 1 a, 1 b. Liquid can also ingressthrough the holes formed by the stitching 3, 4. For this reason, it isconventional to apply a hot-melt seam sealing tape across the seam suchthat it seals to the material on either transverse side of the seam.This is shown in step 4), wherein a seam seal tape 5 has been appliedacross the seam. Seam seal tape is conventionally applied by applying aheated air stream to melt the hot melt adhesive applied to one side ofthe seam seal tape and pressing the seam seal tape against the seamusing pressure rollers, whereby the hot melt adhesive is pressed intothe yarns of the fabric such that the seam seal tape becomes securelyadhered to the underlying fabric.

As mentioned previously, a problem with this conventional procedure isthat the seam seal adhesive, while filling the spaces between adjacentyarns, does not penetrate into the interstices between filaments, etc.,within the yarn itself. These interstices provide a route for liquid towick through the seam in the direction of the arrows A. Thus, liquidenters the seams either between the adjacent pieces of material orthrough the stitching holes. It is then able to wick out in thedirection of the arrows A, particularly under severe weather conditionsor liquid challenges.

The problem is illustrated further in FIG. 2, which is a cross-sectionalong line B-B′ across the area where the seam seal tape 5 is adhered tomaterial 1 b on one side of the seam area. The material 1 b includes aliner material laminated thereto composed of individual yarns 6, eachyarn is made up of a number of individual filaments, etc. The hot meltadhesive 7 on one side of the seam sealing tape 5 can be seen to havepenetrated into the spaces between the yarns 6 but has not penetratedinto the interstices between the individual filaments, etc., of theyarns. The pathways for potential liquid ingress A are shown again.

A second problem with the conventional seam sealing process is that thechoice of liner layer fabrics which may be seam sealed is currently verylimited. One reason for this is that complex textile liner layersrequire a great deal of heat and pressure to drive the adhesive into thespaces between the liner yarns and to form a strong bond with theunderlying protective layer, which is not only time consuming to obtaina reliable seal, but costly as well. In addition, if too much pressureis applied between the seam seal rollers, the pattern of the linermaterial itself may impress through to the front face of the fabric(i.e., material 1 a and 1 b) and appear as an undesirable aesthetic.Even at such high pressures, formation of a reliable seam cannot beguaranteed.

In order to overcome these problems, the textiles used for the linerlayer, or sealing side, of the laminate have been limited to somewhatopen structures, such as relatively simple knits, to allow easypenetration of sealing adhesive. Mono-filament or low-filament count(e.g., 12-13 filament count or less) knits, which have a relatively openstructure, are the easiest structures to durably seal for liquidproofapparel and are conventionally used to avoid the challenges of sealingthe interstices of more complex multi-filament textiles.

In order to overcome the sealing limitations of textile structuresidentified above, a great deal of innovation has been directed todeveloping lower viscosity adhesives that can penetrate and seal complextextile structures. In U.S. Pat. No. 6,387,994, Gore et al. describe theuse of solid solvent as a method to lower adhesive viscosity to allowadhesives to penetrate and seal somewhat more complex structures such asbrushed knits. In PCT Publication No. WO 01/26495 A1, Dunham et al.describe the use of a liquid thermoset adhesive such as silicone in aneffort to seal even more complex or thicker structures. All of theseapproaches, however, have limitations not only with respect to thethickness and complexity of textile structures that can be sealed, butalso in the ease of manufacturing such garments.

In the footwear industry, skiving is a technique used to prepare theedges of two relatively thick and stiff leather pieces to be joined atseams. The skiving reduces the leather thickness for easier joining ofthe stiff components and helps to prevent thick seams that could rub andbe uncomfortable to the wearer. These seams are typically notwaterproof. Skiving has also been used to improve the formability ofleather in the lasting region, or margin, of the upper to reduce thethickness of leather being turned in a tight radius as would occurduring the lasting process of footwear formation when joining theleather upper to the stiff insole board. In some instances in theproduction of waterproof footwear, a protective lining has been skivedin addition to the leather to reduce wrinkling along the lasting marginand to allow attachment of the lining to a waterproof insole board in awaterproof manner. However, such constructions are limited to theproduction of footwear.

The production of liquidproof and breathable soft shell garments havingflexible and durably liquidproof seams is highly desirable and does notexist currently in the apparel industry. A “soft shell” is defined as alaminate with one or more complex textiles, such as a laminate with awoven durable outer textile and a soft, fleece-like or other complextextile lining which provides a sensation of comfort to the wearer. Todate, commercially available liquidproof, breathable three-layerlaminates and garments have been restricted to brushed knit liner layersof limited complexity and limited thickness to permit adequateliquidproof sealing of the seams; alternatively, garments having fleeceliner layers have been sold, but they are not liquidproof at the seam,as it is not possible to seal through the complex textile structures onthe inside or outside of the garment.

Apparel incorporating selectively permeable films or impermeable filmsthat are used as chemical barriers for chemical protection or evenprotection against chemical and biological warfare agents are alsosubject to the same limitations as liquidproof breathable apparel withliquidproof seams. In these applications it would be especially desirousto use three-layer (or more) laminate structures with complex textilestructures to provide additional protection to the barrier layer, suchas from puncture or abrasion during use. To date, no such protectiveapparel with these features exists.

In addition, reversible protective garments incorporating three-layer(or more) laminate structures incorporating complex textiles on bothsides would be highly desirable, particularly if the garments could bemade with durably liquidproof seams. Current reversible garmentconstructions made with such textiles are only water-resistant and notavailable in a truly liquidproof form, as there has been no means tocreate a durably liquidproof seam with durable, complex textilestructures on both sides of a protective laminate. Sealing through thetextile structure is even more difficult when both sides are treatedwith water and stain repellent treatments, such as SCOTCHGARD® coatingsfrom 3M or TEFLON® textile treatments from DuPont, as would be typicalin these applications.

Accordingly, a need exists in the apparel industry for a reliable andeffective technique for joining two or more panels of a complex textilelaminate construction to form a flexible liquidproof seam in protectivegarments.

Definitions

“Laminate” is a protective film or coating that is coated onto oradhered to at least one layer of textile.

“Protective layer”, “barrier layer”, “functional layer”, or “film” aredefined as a film or coating that provides a barrier to liquid waterpenetration as a minimum, and ideally to a range of liquid chemicalchallenges. The layer is considered liquidproof if it prevents liquidwater penetration against a pressure of at least 0.07 bar for a durationof at least 3 minutes. The protective layer material preferablyguarantees a water penetration pressure of more than 0.07 bar. The waterpenetration pressure is measured on a liquidproof panel based on thesame conditions described with respect to the Suter Test for LiquidproofSeams, described herein.

“Seam” is defined as the area where 2 or more pieces of laminate arepermanently joined together by sewing, gluing or other mechanicaljoining

“Liquidproof seam” is a seam that will not leak or weep liquid whenchallenged with a test fluid at a pressure of at least 0.07 bar for aduration of at least 3 minutes. The test fluid is at minimum water, andideally can be a range of liquid chemicals.

“Durably liquidproof seam” is defined as a seam that will not leak orweep fluid when challenged with a test fluid at a pressure of at least0.07 bar for a duration of 3 minutes after 5 machine wash and dry cyclesbased on the Test for Durably Liquidproof Seams, described herein. Thetest fluid is at a minimum water, and ideally can be a range of liquidchemicals.

“Skiving” is defined as the removal of material or textile by cutting,grinding, sanding, abrading or the like from the laminate in the portionof the laminate where a sealed seam will eventually be formed, betweentwo or more protective laminate panels.

SUMMARY OF THE INVENTION

It is a purpose of this invention to provide new and improvedliquidproof seams for garments and the like, as well as an improvedmethod for reliably and durably sealing the seams, between two or morelaminate panels having a complex textile layer on at least the sealingside of the panels to form liquidproof protective garments and similarflexible textile constructions. The improved seam constructions of thepresent invention do not suffer from the durability and leakagelimitations of conventional garments having complex textile structures.Thus, the present invention provides the capability for producing a newclass of protective apparel that has not been possible in the existingart.

The articles of this invention are made by skiving at least a portion ofthe complex textile material from the sealing area of the laminate panelprior to joining two or more laminate panels by a seam. As used herein,the terms “skive,” or “skived,” or “skiving” refer to the selectiveremoval of textile material by cutting, grinding, sanding, abrading, orthe like.

The skiving may be carried out using any technique, equipment or toolwhich selectively removes the complex textile material in the desiredregion or regions of the laminate panel to reduce the thickness of thecomplex textile layer in at least a portion of the sealing region. Inone preferred embodiment, the skiving of the complex textile isaccomplished by using a skiving machine which has a cutting blade and amaterial feed apparatus for orienting the complex textile layer adjacentthe cutting blade to remove material. The Fortuna ES-50 skiving machine,available from Fortuna GmbH, is one example of a skiving apparatusparticularly suited to selectively remove textile material due to thefine skiving depth adjustment range of the machine.

In a preferred method for producing a garment of the present invention,the pieces of protective laminate are cut into pattern pieces as wouldbe done in normal apparel assembly processes. The sealing regions along,for example, the edges of these cut pieces to be sewn are identified,and these edges are passed through the skiving machine to remove atleast a portion of the complex textile material in a desired width.Further, it is possible to remove selected regions of textile materialfrom the interior of the panels so as to form sealing regions for theattachment of pockets, tunnels, hoods, or the like, to the garment, oralternatively, for attaching patches, embroidering logos or other suchfeatures. The complex textile is preferably essentially completelyremoved, but complete removal is not a requirement. It is only necessaryto remove a sufficient amount of the complex textile so that theremaining structure is easily sealed through and any remaining filamentscan be encapsulated during subsequent sealing steps. Alternative methodsof skiving textile material from selected areas, such as by sanding,grinding, shearing and the like, are also within the scope of thisinvention.

When forming sewn seams between two or more laminate panels, the widthof the sealing region on or in the protective laminate panel istypically chosen such that it is wider than the seam allowance requiredfor sewing, thus leaving an open area on each side of the seam allowanceafter the laminate panels are sewn together. In a preferred method forforming a durably liquidproof seam, a seam sealing tape is then appliedto the joined laminate panels. The sealing region (i.e., the skivingwidth), seam allowance and sealing tape width are selected such thatthere is at least some width (e.g., preferably 2 mm or more) of open orskived surface on each side of the seam allowance prior to theapplication of the sealing tape. Upon addition of the sealing tape, theentire sealing region is covered with sealing adhesive, and mostpreferably, the tape extends slightly beyond the sealing region onto thesurface of the remaining un-skived complex textile layer. Thisconfiguration is not only the most aesthetically pleasing, but also thedurability of these seams is improved when the adhesive restrains theskived edge of the textile layer and the tape is anchored to both theprotective film surface and to the laminated textile (i.e., un-skived)surface. In one example of a particularly preferred sealingconfiguration of the invention, the width of the sealing region beyondthe seam allowance is about 4 mm and the amount of sealing tape thatextends onto the textile is about 6 mm.

In performing the skiving step, it is preferred to remove as much of thetextile as possible in the sealing region, while being careful to notdamage the protective layer on the laminate piece to a point where aliquidproof seam cannot be created. This can be accomplished byadjusting the skiving equipment to cut as much textile as is desirablewithout unnecessarily compromising the integrity of the protectivelayer. In a most preferred embodiment, the protective layer is undamagedby the skiving.

In an alternative embodiment of the present invention, the skiving canbe carried out after the laminate panels have been sewn together.Particularly, a seam can be created between two protective laminatepanels, then the skiving step is carried out to reduce the textilematerial in the sealing region. Care must be take when practicing thismethod to avoid damaging the seam (e.g., the sewing thread, adhesivebead, or the like), which may result in finished apparel that could besubject to durability issues.

The ability to fabricate protective apparel having complex textilestructure layers on both sides of a three- (or more) layer laminate is ahighly desirable configuration, especially when the apparel has durablyliquidproof seams. For example, in one aspect of the current invention,completely liquidproof garments can be made having a woven protectivetextile on the exterior of the garment, and a soft insulating fleece onthe interior side of the garment and which have liquidproof seamscreated by skiving away the fleece in the seam area prior to sealing.

The protection of the liquid barrier layer by a complex textilestructure on both sides of the barrier also allows the production ofreversible garments. In these reversible garments, it is desirable tooffer protection against thorns, abrasion, tears and the like on bothsides, as during use of the garment both sides will be exposed to suchwear hazards. Such reversible garments provide the opportunity fordurably liquidproof protective garments in applications heretofore notavailable. For example, the use of two different camouflage patterns,such as desert tan on one side and forest on the other side, would bedesirous for military applications, or alternatively, black on one sidefor night operations and camouflage on the other for use by specialforces. Durably liquidproof protective police garments could befabricated with, for example, orange or another bright or reflectivecolor on one side and blue (or other standard police uniform color) onthe other. Hunting garments could offer different patterns for waterfowl and land hunting, as an example. As noted earlier herein, todayreversible garments incorporating complex textile structures on bothfaces of the garment are only water resistant and are not available in atruly liquidproof form.

In another embodiment of this invention, two-layer laminate panelshaving a complex textile structure on the sealing side can be sealedwithout sewing by skiving the textile away in the sealing regions of thepanels to be joined. The two protective films can then be glued directlyto each other to form a seal without having to penetrate and form a sealthrough the textile itself. A small section of the non-skived textilemay be included in the seam area to increase the mechanical strength,but it is not necessary to seal to the non-skived textile portion, asthe waterproof seal occurs at the film surface that has been exposed byskiving. This seam allowance would typically be folded over and glueddown to reduce stress on the liquidproof joint that has been formed.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows schematically the steps in the formation of one type ofconventional seam, which is sealed with seam sealing tape.

FIG. 2 is an enlarged cross-sectional view along the line B-B′ of FIG.1.

FIG. 3 shows a cross sectional view of a three layer laminate prior toskiving, sewing, or sealing.

FIG. 4 shows a cross sectional view of a three layer laminate that hasbeen skived, prior to sewing or sealing.

FIG. 5 shows a cross sectional view of a top-stitched simple seamconfiguration between three layer laminate panels formed by skiving,sewing and sealing with seam tape.

FIG. 6 shows a cross sectional view of another embodiment of a simpleseam configuration between three layer laminate panels formed byskiving, sewing and seam taping.

FIG. 7 a shows a cross sectional view of a two layer laminate panelwhere the complex textile structure has been skived to form a sealingregion and FIG. 7 b shows a finished glued seam between two such twolayer laminate panels.

FIG. 8 shows a cross sectional view of a top-stitched simple seambetween four layer laminate panels formed by skiving, sewing and sealingwith seam tape.

FIG. 9 shows a top perspective view of a laminate panel in the form of afront panel of a jacket, wherein the edges, or sealing regions, of thepanel have been skived.

FIG. 10 shows a top perspective view of a laminate panel similar to thatof FIG. 9 wherein an additional sealing region has been created in theinterior of the panel by skiving.

FIG. 11 shows a top perspective view of a laminate panel in the form ofa rectangular pocket, wherein the edges, or sealing regions, of thepanel have been skived.

FIG. 12 shows a top perspective view of the laminate panel of FIG. 10with the pocket panel of FIG. 11 oriented on the laminate panel withinthe interior sealing region so that the pocket sealing region and thepanel internal sealing region are adjacent one another.

FIG. 13 shows a top perspective view of the combination of FIG. 12,wherein the pocket is sealed to the laminate panel with seam sealingtape.

FIGS. 14 a and 14 b are alternative embodiments of cross-sectional viewsalong the line D-D′ of FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a new and improved method for reliablyand durably sealing the seams between two or more laminate panels havinga complex textile construction to form flexible liquidproof protectiveapparel. The improved seam construction of the present invention doesnot suffer from the durability and leakage limitations of conventionalseams constructed with laminates having complex textile structures.Thus, the present invention provides the capability for producing a newclass of protective apparel that has not been possible through the useof the existing art.

Referring to FIG. 3, there is shown a cross-sectional view of a threelayer textile laminate panel 10 having a sealing side 18 for joining thelaminate panel to another laminate panel (not shown). The laminate panel10 includes a complex textile layer 12 on the sealing side 18, a barrierlayer 14 and a second textile layer 16, which may or may not comprise acomplex textile. FIG. 4 shows the textile laminate panel of FIG. 3 witha portion of the complex textile layer 12 removed by skiving to revealsealing region 20. Two or more textile laminate panels are then joinedin the present invention as shown in cross-section in FIG. 5.Particularly, in the embodiment shown, the two laminate panels 10 a and10 b are sewn together with stitches 22 joining the laminate panelstogether and stitches 25 holding down, or “top-stitching,” the seamallowance between the stitches 22 and the edges of the panels 10 a and10 b. Seam sealing tape 24 covers and adheres to the joined panel edgesand the sealing regions 20 and extends and adheres onto a portion of thecomplex textile layer 12 beyond the sealing regions 20. With thisconstruction, a durably liquidproof seam can be created where the seamtape 24 is anchored to both the barrier layer 14 in the sealing region20 and to the complex textile (i.e., un-skived) layer 12.

An alternative construction of a durably liquidproof taped seam is shownin FIG. 6, wherein rather than a top-stitched seam, a simplesingle-stitched seam is incorporated. During the seam taping step, theseam allowance beyond stitches 22 may fall to either panel side, and thesealing regions 20 are provided to be sufficiently wide that the seamtape will adhere to the barrier layer 14 in the sealing region.

FIGS. 7 a and 7 b show an alternative embodiment of a two layerconstruction suitable for creating a liquidproof seal of the presentinvention. Specifically, FIG. 7 a shows a two layer laminate panel 30with a complex textile layer 12 and a barrier layer 14, with a portionof the complex textile layer 12 removed by skiving to reveal sealingregion 20. FIG. 7 b shows in cross-section two laminate panels 30 a and30 b joined together in the present invention. In this embodiment, anadhesive 32 joins the sealing regions 20 of the two panels together,then the sealed region is folded over and a second adhesive 34 holds thefolded portion to the surface of the joined laminate panel structure.

FIG. 8 shows a further alternative embodiment of the invention, whereinmulti-layer laminate panels, in this case four layer laminates, arejoined. Particularly, the four layer laminate panels 40 a and 40 b, eachcomprising complex textile layer 12, barrier layer 14, second textilelayer 16 and additional textile layer 42, are sewn together withstitches 22 joining the laminate panels. Seam sealing tape 24 covers andadheres to the joined (stitched) panel edges and the sealing regions 20and extends and adheres onto a portion of the complex textile layers 12beyond the sealing regions 20. With this construction, a durableliquidproof seam is created where the seam tape 24 is anchored to boththe barrier layer 14 in the sealing region 20 and to the complex textile(i.e., un-skived) layer 12.

FIG. 9 is a perspective view of a three layer laminate panel 50 for afront panel of a jacket, wherein the edges, or sealing regions 20, oncomplex textile face 70 of the panel have been skived in preparation forsealing. FIG. 10 is a perspective view of the laminate panel 50 of FIG.9 with a further internal sealing region 52 formed by skiving asubstantially rectangular geometry which is oriented for adding a pocketto the laminate panel 50 with a liquidproof seam.

FIG. 11 is a perspective view of a laminate panel 60, which in thisembodiment is in the form of a substantially rectangular pocket with thesame three layer construction as the jacket panel 50, and sealing region62 has been created by skiving the outer perimeter of the panel 60 oncomplex textile face 72. FIG. 12 depicts the jacket panel 50 of FIG. 10with the pocket panel 60 of FIG. 11 oriented within the internal sealingregion 52 so that the pocket sealing region 62 is adjacent the jacketinternal sealing region 52, as shown, in preparation for attaching thepocket to the jacket in a liquidproof manner. FIG. 13 depicts the pocketpanel 60 joined to the jacket panel 50 with seam tape 66, creating aliquidproof seal between the panels. FIG. 14 a is a cross-sectional viewof the sealed seam of FIG. 13 along line G-G′, wherein the seam tape 66bridges and seals the sealing region 62 of the pocket panel 60 to thesealing region 52 of the jacket panel 50. In this embodiment, sealingregion 62 extends under the pocket panel 60. FIG. 14 b is an alternativeembodiment of a cross-sectional view of the sealed seam of FIG. 13 alongline G-G′, wherein the end of the sealing region 62 is substantiallyflush with the edge of pocket panel 60. Additionally, FIG. 14 b depictsan optional stitch line 68. These alternative orientations andconfigurations are exemplary only, and other such alternatives are alsowithin the scope contemplated for the present invention.

The barrier layer of the laminate may be a protective membrane, film orcoating. It may be selected from the group of materials including, butnot limited to, polyesters, polyamides, polyketones, polysulphones,polycarbonates, fluoropolymers, polyacrylates, co-polyether esters,co-polyether amides, polyurethanes, polyvinylchloride,polytetrafluoroethylene or polyolefins. For waterproof breathableapplications the first layer is preferably, formed from expandedpolytetrafluoroethylene (ePTFE). Expanded polytetrafluoroethylene isknown to be very waterproof and highly breathable. The ePTFE may beprovided with a coating of a hydrophilic polymer in known manner. Suchlaminates may preferably provide a water-vapour transmission rate ofgreater than 1500 g/m²/day (particularly greater than 3000 g/m²/day) anda water entry pressure of greater than 0.07 bar for a period of at leastthree minutes. For chemical protective application, laminatesincorporating impermeable or selectively permeable layers such as GORECHEM-PAK® fabrics, available from W.L. Gore and Associates, Inc.(Elkton, Md.) would be preferred.

Suitable laminate layers for the sealing side(s) of the apparel of thisinvention include textiles with a complex textile geometry, as describedearlier herein. As noted, textiles with a complex textile structure havea fiber, or filament, structure (whether mono-filament ormulti-filament) having a tortuous path through which liquid adhesiveshave limited ability to penetrate to the protective barrier layer and toencapsulate the filaments of the textile layer in order to form aliquidproof seam. Complex textile structures can include, for example,wovens, nonwovens, knits, and brushed, fleeced or otherwise napped (i.e,any suitable raised surface) forms thereof.

Additional textile layers, whether complex or otherwise, may be suitableon or in the laminates contemplated in the present invention, dependingon the requirements of the finished apparel.

Lamination of materials for the novel liquidproof seaming techniques ofthis invention may be carried out by any suitable conventionallamination techniques. For example, in one technique, a dot pattern ofadhesive may be applied onto one or more of the layers to be joined by agravure roll, and lamination then occurs by passing the materialsbetween the pressure rollers and curing.

In order to produce protective apparel a pattern is used to cut severalpieces of protective laminate into panels that will be joined togetherat seams to form a three dimensional article, with features such assleeves in a jacket or legs in a pair of pants. Optionally additionalfeatures such as hoods and pockets will be included to improve theaesthetics and functionality of the apparel. If the apparel is to betruly protective, it is critical to be able to join these cut panels oflaminate together in a manner that the seams or joints where two or morepieces of laminate come together are made liquid proof.

Apparel made from selectively permeable films or impermeable films thatare used as chemical barriers for chemical protection or even protectionagainst chemical and biological warfare agents also benefit from theability to use more complex textiles and form apparel with liquidproofseams. In these applications it is especially desirous to use threelayer laminate structures to protect the barrier layer from puncture orabrasion during use.

It will be apparent to one of skill in the art that any suitablelaminates may be used in forming the liquidproof seams of the presentinvention, and that other suitable materials, skiving techniques andsealing steps are also contemplated as within the scope of the presentinvention. Embodiments of the present invention will now be described byway of example only with reference to the following examples.

Tests

Suter Test for Liquidproof Seams

To determine whether a protective barrier fabric or the seams of agarment made from the protective barrier fabric are waterproof, theSuter test procedure is used, which is based generally on thedescription in ISO 811-1981. This procedure provides a low pressurechallenge to the sample being tested by forcing water against one sideof the test sample and observing the other side for indication thatwater has penetrated through the sample.

The sealed seam test sample is clamped and sealed between rubber gasketsin a fixture that holds the sample so that water can be applied to anarea of the sample 3 inches in diameter (7.62 cm). The water is appliedunder air pressure of 1 psig (0.07 bar) to one side of the sample. Intesting a fabric laminate, the water would be applied to the face orexterior side. In testing a sealed seam, water is applied to the faceside of the sample and the opposite side, or seam backer layer, isobserved for leaks.

The opposite side of the sample is observed visually for any sign ofwater appearing (either by wicking or the appearance of droplets) at theseam edge for 3 minutes. If no water is observed, the sample has passedthe test and the sample is considered liquidproof.

Test for Durably Liquidproof Seams

To determine the durability of a liquidproof seam, the seam sample iswashed and dried generally following the conditions outlined in ISO6330:1984 Procedure No. 3B. Specifically, the sample is loaded in a 4pound (about 2 Kg) load of laundry into a top loading washing machineset to a medium water level (18 gallons, or equivalently 0.0681 m³), hotwater temperature (140° F., or equivalently, 60° C.), warm rinse cycleand heavy duty wash cycle set for 10 minutes, with 90 g of TIDE®powdered laundry detergent. The load is then dried in a rotating dryeron a Hot setting for a 35-45 minute drying time. This wash/dry regimenis repeated five times.

The seam sample is then subjected to the Suter Test for LiquidproofSeams, described above. If no water is observed upon testing, the samplehas passed the test and the sample is considered durably liquidproof.

EXAMPLES Example 1

A liquidproof seam was formed between two laminate panels in thefollowing manner.

A three-layer textile laminate was formed comprising a composite barriermembrane sandwiched between two textile layers. The composite barriermembrane was a composite of microporous polytetrafluoroethylene (PTFE)membrane coated with a polyurethane, prepared according to U.S. Pat. No.4,194,041 using a water vapor permeable, nonporous polyurethane coatingon the ePTFE. This membrane was laminated on one side, using a pluralityof dots of moisture cureable polyurethane adhesive, to a Nylon/Spandexwoven textile layer approximately 0.4 mm thick and having a weight ofapproximately 150 grams per square meter. The other side of the membranewas laminated, again using a plurality of dots of moisture cureablepolyurethane adhesive, to a polyester fleece textile approximately 0.6mm thick and having a weight of approximately 170 grams per squaremeter. Two panels having rough dimensions of about 0.15 m by 0.6 m werethen cut from this three-layer textile laminate.

A sealing region of approximately 19 mm width was created along one edgeof each laminate panel by removing approximately 0.6 mm of fleecematerial thickness by skiving. This skiving was accomplished using aFortuna ES-50 Skiving machine equipped with a Fortuna stone feed rollerand curved narrow guide piece (Fortuna Gmbh, Weil der Stadt, Germany).

The laminate panels were then joined at their respective sealing regionsby sewing in a straight line, 13 mm from the panel edge, using a Jukisewing machine (Model No. DLN-415-5, Juki Corporation, Tokyo, Japan),set to 5.1 stitches per cm, followed by trimming of 11 mm off the seamallowance to ensure that the edge of the resultant 2 mm seam allowancewas at least 4 mm from the edge of the textile in either of thenon-sealing regions.

A 22 mm width seam tape (GORE SEAMS seam tape obtained from W.L. Goreand Associates, Elkton, Md.), having a hot melt polyurethane adhesive,was then applied to the sealing region by heating the seam tape to atemperature sufficient to melt the polyurethane adhesive and passing thetape and seam through the nip of a pair of pressure rollers in order tosqueeze the molten adhesive onto the protective layer surface so as toensure good bonding of the tape to the surface. The tape width was suchthat it covered the entire sealing region and extended about 5 mm beyondthe sealing region on each laminate panel. The resulting seam betweenthe two laminate panels was tested using the Suter Test for LiquidproofSeams and determined to be liquidproof based on passage of a 0.07 bar/3min challenge. The seam was then subjected to the Test for DurablyLiquidproof Seams, and after the wash/dry regimen, the sample againpassed the 0.07/3 min challenge. As a further evaluation, the sample wasthen subjected to a more rigorous seam challenge of 3 psi (0.22 bar)/2min in the Suter test rig, and no water was observed; thus, the sampleremained durably liquidproof under the more rigorous conditions.

Example 2

A liquidproof seam was formed between two laminate panels in a mannersubstantially as described in Example 1, with the following exceptions.

The three-layer textile laminate was formed comprising a compositebarrier membrane sandwiched between two textile layers. The membrane waslaminated on one side, using a plurality of dots of moisture cureablepolyurethane adhesive, to a polyester knitted textile layer ofapproximately 0.3 mm thickness and having a weight of approximately 85grams per square meter. The other side of the membrane was laminated,again using a plurality of dots of moisture cureable polyurethaneadhesive, to a polyester fleece textile layer approximately 6 mm thickand having a weight of approximately 200 grams per square meter.

A sealing region of approximately 19 mm width was created along one edgeof each laminate panel by removal of approximately 6 mm of fleecematerial thickness by skiving.

A 25 mm width seam tape (GORE SEAMS seam tape obtained from W.L. Goreand Associates, Elkton, Md.), having a hot melt polyurethane adhesive,was then applied to the sealing region by heating the seam tape. Thetape width was such that it covered the entire sealing region andextended about 6 mm beyond the sealing region on each laminate panel.The resulting seam between the two laminate panels was tested using theSuter Test for Liquidproof Seams and determined to be liquidproof basedon passage of a 0.07 bar/3 min challenge.

Example 3

A liquidproof seam was formed between two laminate panels in a mannersubstantially as described in Example 1, with the following exceptions.

The laminate was identical to that described in Example 1. However,rather than skiving the fleece side of the three-layer laminate, asealing region of approximately 19 mm width was created along one edgeof each laminate panel by removal of approximately 0.4 mm of theNylon/Spandex woven material thickness.

The resulting seam between the two laminate panels was tested using theSuter Test for Liquidproof Seams and determined to be liquidproof basedon passage of a 0.07 bar/3 min challenge.

Example 4

A laminate panel attachment, sewn to the center of a second laminatepanel, which does not compromise the liquidproofness of the secondlaminate panel, was formed in the following manner. Two laminate panels,identical in composition to those described in Example 1, the firsthaving rough dimensions of about 0.3 m×0.3 m, and the second havingdimensions of about 0.1 m×0.1 m were used.

A sealing region of approximately 8 mm width was created along theperimeter of the laminate panel attachment by removal of approximately0.6 mm of fleece material thickness by skiving. This skiving wasaccomplished using a Fortuna ES-50 Skiving machine equipped with aFortuna stone feed roller and curved narrow guide piece (Fortuna Gmbh,Weil der Stadt, Germany). A second sealing region of approximately 25 mmwidth was created in a square geometry within the main laminate panel byremoval of approximately 0.6 mm of fleece material thickness by skiving.This square sealing region was accomplished using the same Fortunamachine with stone feed roller, however, in this case the curved narrowguide piece was removed and the desired region to be skived was run flatalong the work table over the cutting blade.

The laminate panels were then joined at their respective sealing regionsby sewing using a commercial Juki sewing machine, 5.1 stitches per cm,ensuring that the resultant seam was at least 4 mm from the edge of thefleece in the non-sealing region.

A 25 mm width seam tape (GORE SEAM® seam tape obtained from W.L. Goreand Associates, Elkton, Md.), which includes a hot melt polyurethaneadhesive, was then applied to the sealing region by heating the seamtape and passing the tape and seam through the nip of a pair of pressurerollers in order to squeeze the molten adhesive onto the protectivelayer surface so as to ensure good bonding of the tape to the surface.The tape width was such that it covered the entire sealing region andextended about 6 mm beyond the sealing region on each laminate panel.The resulting laminate panel with attachment was tested using the SuterTest for Liquidproof Seams and determined to be liquidproof based onpassage of a 0.07 bar/3 min challenge.

1. A method of joining laminate panels comprising: (1) providing atleast two laminate panels, each said laminate panel including (a) atleast one layer of textile material having a thickness, and (b) at leastone liquidproof barrier layer affixed to the textile material; (2)skiving at least a portion of the textile material to remove at least aportion of the thickness, thereby forming a sealing region in each ofthe at least two laminate panels, said sealing regions having athickness in at least a portion thereof which is less than the thicknessof the remainder of the laminate; and (3) joining together the sealingregions of the at least two laminate panels by forming at least oneliquidproof seam therebetween.